The aetiology of lichen planus is unknown, but it is often connected with i
nfections. In recent Sears peptic ulcer disease has also been closely linke
d with an infections agent, Helicobacter pylori. A case-control study was c
onducted in 78 patients with lichen planus to find out a previous history o
f peptic ulcer disease, using a questionnaire and a medical record review.
Patients were also asked about family history in first- and second-degree r
elatives. Fifty-seven patients with other skin diseases were interviewed as
controls. The prevalence of H, pylori infection in patients with lichen pl
anus was compared to that of 39 patients with other skin diseases and to th
e overall prevalence rates of H, pylori infection in Finland, Our findings
are consistent with an approximately three-fold increased risk of peptic ul
cer in patients with chronic/repeating lichen planus, when compared to the
control patients (p = 0.04) and also to the overall peptic ulcer prevalence
rates in Finland, Forty-one percent of the patients with chronic/repeating
lichen planus had a first- or second-degree family member with a peptic ul
cer, while the corresponding rate in the control group was only 12% (p=0.00
3). The prevalence of H, pylori infection in patients with chronic/repeatin
g lichen planus and transient lichen planus was not significantly different
from that in patients with other skin diseases.